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961.
962.
为了解沈阳市0~7岁儿童全血铜、锌、钙、镁、铁元素缺乏情况,探讨性别、年龄与5种元素含量之间的关系,对沈阳市20335名0~7岁儿童进行末梢指间采血,用BH5100型原子吸收光谱仪测定了全血中钙、镁、铜、铁、锌的含量。结果表明,儿童血锌平均水平低于正常值范围,缺乏最严重,缺乏率为77.78%;血铜、锌、铁缺乏率与年龄有线性相关关系,且随着年龄的增加呈现下降趋势(P〈0.05),下降速度在40%~60%之间;全血中5种元素均存在年龄差异(P〈0.01),血铜元素男童明显高于女童(P〈0.01)。提示儿童应加强膳食干预,提高各种富含微量元素的食物摄人,以促进儿童的生长发育。  相似文献   
963.
细胞微环境的稳定是保持细胞正常增殖、代谢和功能活动的重要条件,微环境成分的异常变化可使细胞发生病变。采用荧光光谱技术研究离体白细胞在多糖微环境中荧光发射特性的变化规律和发光机制,并进一步的分析了多糖对白细胞的生物活性的影响。实验结果表明:当白细胞受波长为407 nm的激光照射时,发射位于450 nm的荧光。在加入脂多糖或葡聚糖时,白细胞的荧光发射峰的位置不会变化,峰值受到影响。脂多糖的加入会减弱白细胞荧光峰强度,且荧光强度随脂多糖浓度(0~500 μg·mL-1范围内)的增加而持续减弱。而葡聚糖可以一定程度增加白细胞的荧光强度,浓度越高,荧光强度越大。分析认为白细胞发射的450 nm荧光来自发射物质烟酰胺腺嘌呤二核苷酸(NADH)。白细胞内NADH随着离体时间的增长,被氧化成不发荧光的烟酰胺腺嘌呤磷酸二核苷酸(NAD+),导致细胞荧光峰值下降,从而引起细胞凋亡。加入脂多糖产生的羟自由基(·OH)会与NADH发生氧化反应,因此脂多糖加速了NADH的消耗,导致白细胞荧光减弱,加快细胞凋亡。而葡聚糖主要是由葡萄糖单体组成,葡聚糖的加入会将NAD+还原成NADH,因此延缓了白细胞的凋亡。分析认为脂多糖可以加速白细胞的凋亡,提高细胞发生炎症甚至是肿瘤的机率,而葡聚糖对白细胞有保护作用。该研究为研究肿瘤的发生和发展过程以及治疗提供有价值的参考。  相似文献   
964.
Using an improved computational fluid dynamics (CFD) method developed for highly unsteady three-dimensional flows, numerical simulations for oscillating flow cycles and detailed unsteady simulations of the flow and forces on the aortic vessels at the iliac bifurcation, for both healthy and diseased patients, are analyzed. Improvements in computational efficiency and acceleration in convergence are achieved by calculating both an unsteady pressure gradient which is due to fluid acceleration and a good global pressure field correction based on mass flow for the pressure Poisson equation. Applications of the enhanced method to oscillatory flow in curved pipes yield an order of magnitude increase in speed and efficiency, thus allowing the study of more complex flow problems such as flow through the mammalian abdominal aorta at the iliac arteries bifurcation. To analyze the large forces which can exist on stent graft of patients with abdominal aortic aneurysm (AAA) disease, a complete derivation of the force equations is presented. The accelerated numerical algorithm and the force equations derived are used to calculate flow and forces for two individuals whose geometry is obtained from CT data and whose respective blood pressure measurements are obtained experimentally. Although the use of endovascular stent grafts in diseased patients can alter vessel geometries, the physical characteristics of stents are still very different when compared to native blood vessels of healthy subjects. The geometry for the AAA stent graph patient studied in this investigation induced flows that resulted in large forces that are primarily caused by the blood pressure. These forces are also directly related to the flow cross-sectional area and the angle of the iliac arteries relative to the main descending aorta. Furthermore, the fluid flow is significantly disturbed in the diseased patient with large flow recirculation and stagnant regions which are not present for healthy subjects.  相似文献   
965.
In the pharmaceutical industry the growing number of samples to be analyzed requires high throughput and fully automated analytical techniques. Commonly used sample-preparation methods are solid-phase extraction (SPE), liquid–liquid extraction (LLE) and protein precipitation. In this paper we will discus a new sample-preparation technique based on SPE for high throughput drug extraction developed and used by our group. This new sample-preparation method is based on monolithic methacrylate polymer as packing sorbent for 96-tip robotic device. Using this device a 96-well plate could be handled in 2–4 min. The key aspect of the monolithic phase is that monolithic material can offer both good binding capacity and low back-pressure properties compared to e.g. silica phases. The present paper presents the successful application of monolithic 96-tips and LC–MS/MS by the sample preparation of busulphan, rescovitine, metoprolol, pindolol and local anaesthetics from human plasma samples and cyklophosphamid from mice blood samples.  相似文献   
966.
An isocratic high-performance liquid chromatographic method has been developed for the measurement of serotonin, 5-hydroxyindolacetic and homovanillic acids in dried blood spots and in platelet poor and rich plasma samples. Analyses were carried out on a C18 reversed-phase column using a mobile phase composed of 13% methanol and 87% aqueous citrate buffer, containing octanesulfonic and ethylendiaminotetracetic acids. Coulometric detection was used, setting the guard cell at +0.100 V, the first analytical cell at −0.200 V and the second analytical cell at +0.400 V. For the pre-treatment of biological samples a novel solid-phase extraction procedure, based on mixed-mode reversed-phase – strong anion exchange Oasis cartridges, was implemented. Extraction yields of the analytes from all these matrices were satisfactory, being always higher than 89.0%. The calibration curve was linear over the on-column concentration range of 0.1–22.5 ng mL−1 for serotonin and 5-hydroxyindolacetic acid and of 0.25–22.5 ng mL−1 for homovanillic acid. The sensitivity was good with a limit of detection of 0.05 ng mL−1 for serotonin and 5-hydroxyindolacetic acid and 0.12 ng mL−1 for homovanillic acid. Results were also satisfactory in terms of precision, selectivity and accuracy. The analytical method was successfully applied to human platelet poor and rich plasma samples and to dried blood spots from volunteers and psychiatric patients.  相似文献   
967.
比较了植物血凝素(PHA)与金色葡萄球菌肠毒素(SEA)对外周血单个核细胞(PBMCs)的刺激效果。取健康人外周静脉血,分离得到PBMCs,分别加入PHA及SEA进行刺激并孵育12 h,利用原子力显微镜和倒置荧光显微镜观察细胞形态变化,利用量子点联合共聚焦显微镜观察活化后细胞膜表面CD3、CD69的分布情况,利用流式细胞术检测淋巴细胞活化早期细胞分化抗原CD69分子表达的变化情况。结果显示,丝裂原PHA刺激的淋巴细胞大多成群聚集,而超抗原SEA刺激的淋巴细胞大多呈分散状,且二者形态有明显差异;两组活化后淋巴细胞的体积均大于静息组,且活化过程中发生极化作用,迁移淋巴细胞,形成膜突起;丝裂原和超抗原刺激淋巴细胞12 h后,使淋巴细胞表达CD69抗原分子,但在量表达上存在差异性(PHA:39.5%±8.7%;SEA:8.3%±1.8%),抗原分子CD3和CD69在膜表面呈不均匀分布,且SEA活化后的T淋巴细胞表面受体CD3和CD69分子在空间上形成了微结构域;外周单个核细胞中其它非T细胞在丝裂原或者超抗原的刺激下也能表达活化抗原分子CD69。  相似文献   
968.
Ein 3radioimmunoassay (RIA) for precise and reliable determination of androstenedione (androst-4-ene-S,17-dione, AD) in endocrinological investigations has been developed. Specific antisera were obtained from rabbits following immunization with the bovine serum albumine conjugate of AD-3- (O-carboxymethyl)oxime. The sensitivity of the method was found to be 18fmol AD per assay tube. The method described has proved to be suitable for determinations of AD values in blood plasma and follicular fluids of cattle and swines.  相似文献   
969.
Specific method for accurate radioimmunoassay of free and total thyroxine in un-extracted serum has been developed. The method is used for estimation of either free thyroxine (T4) or total T4 by inhibition of the binding sites of T4 to protein using TCA/NaOH mixture. The antibodies used in this study were obtained from Mallinkrodt. The separation technique used in our modification is that of dextran charcoal, this is to absorb the free fractions on charcoal.

The kinetics of antibody antigen combination, the parameters of the experiment like; charcoal concentration, antibody dilution, temp., time of incubation and radioactivity concentration were, studied to optimize the standard curve and the sensitivity of T4RIA.

Serum samples of different thyroid cases were investigated for determination of free and total T4 concentration to get the levels for each group of which 50 normals, 57 hyperthyroidism and 21 hypothyroidism in comparison with the classical tests of thyroid functions. Also sensitivity and variance coefficient has been carried out in comparison with other T4RIA techniques.  相似文献   
970.
《Analytical letters》2012,45(1-3):483-502
Blood studies for clinical screening/analysis are geared toward point of care testing. Flow based techniques have expanded their applications with unique approaches that may be adaptable for use as alternative disease screening/diagnosis. Many newly developed systems for solution based chemical analysis can be easily adapted for use with plasma and serum. However, cell and intracellular analyses are different. Blood cell analyses require a particular way of sample introduction and detection. This review emphasizes the applications of flow based techniques, especially those that were coupled with FI/SI, in clinical studies through analysis of red blood cells and their intracellular substances.  相似文献   
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